org.apache.hadoop.hbase

Class MetaRegionLocationCache

java.lang.Object

org.apache.hadoop.hbase.zookeeper.ZKListener

org.apache.hadoop.hbase.MetaRegionLocationCache

@InterfaceAudience.Private
public class MetaRegionLocationCache
extends ZKListener

A cache of meta region location metadata. Registers a listener on ZK to track changes to the meta table znodes. Clients are expected to retry if the meta information is stale. This class is thread-safe (a single instance of this class can be shared by multiple threads without race conditions).

Field Summary

Fields inherited from class org.apache.hadoop.hbase.zookeeper.ZKListener

watcher

Constructor Summary

Constructors

Constructor and Description
MetaRegionLocationCache(ZKWatcher zkWatcher)

Method Summary

Modifier and Type	Method and Description
Optional<List<HRegionLocation>>	getMetaRegionLocations() Returns Optional list of HRegionLocations for meta replica(s), null if the cache is empty.
void	nodeChildrenChanged(String path)
void	nodeCreated(String path)
void	nodeDataChanged(String path)
void	nodeDeleted(String path)

Methods inherited from class org.apache.hadoop.hbase.zookeeper.ZKListener

getWatcher

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

MetaRegionLocationCache

public MetaRegionLocationCache(ZKWatcher zkWatcher)

Method Detail

getMetaRegionLocations

public Optional<List<HRegionLocation>> getMetaRegionLocations()

Returns Optional list of HRegionLocations for meta replica(s), null if the cache is empty.

nodeCreated

public void nodeCreated(String path)

Overrides:

nodeCreated in class ZKListener

nodeDeleted

public void nodeDeleted(String path)

Overrides:

nodeDeleted in class ZKListener

nodeDataChanged

public void nodeDataChanged(String path)

Overrides:

nodeDataChanged in class ZKListener

nodeChildrenChanged

public void nodeChildrenChanged(String path)

Overrides:

nodeChildrenChanged in class ZKListener